Water-ingress-preventing mechanism for lotion pump

Abstract

The invention provides a water-ingress-preventing mechanism for a lotion pump. The mechanism is mainly used for a lotion pump mounted on a container with a liquid therein and is able to effectively prevent foreign liquids from entering the container. According to one aspect of the invention, in the locking tube portion ( 13 ) of the press head ( 10 ) is formed at least one longitudinal slot ( 15 ) which extends upwards from the lower end edge of the locking tube portion over at least part of the length of the locking tube portion. The slot is disposed such that the upper end of the slot is at a position above the top surface ( 25 ) of the cylinder cover ( 20 ) when the press head is pressed down to and at the lower stop position of its press stroke with respect to the cylinder cover. According to another aspect of the invention, the external thread ( 14 ) on the locking tube portion extends helically upwards from the lower end edge of the locking tube portion, whereas the internal thread ( 26 ) in the central through-hole ( 21 ) in the cylinder cover extends helically downwards from the upper end edge of the central through-hole. The features in the both of the two aspects effectively prevent foreign liquids from being sucked into the container during operation of the lotion pump.

The invention claimed is: 
     
       1. A water-ingress-preventing mechanism for a lotion pump, comprising:
 a press head, in which a passage is formed, a locking tube portion being formed around a lower end opening of the passage and vertically extending downwards from a body of the press head, an external thread being formed on an outside wall of the locking tube portion; 
 a connecting conduit, an upper end of which is fixed to the lower end opening of the passage of the press head so as to communicate with the passage; and 
 a cylinder cover, which has a central through-hole for the connecting conduit to pass, a water-ingress-preventing guide sleeve being provided on an inside wall surface of a lower portion of the central through-hole to vertically extend beyond a top surface of the cylinder cover, the fit between an inside wall surface of the water-ingress-preventing guide sleeve and an outside wall surface of the connecting conduit being a slide fit with a clearance therebetween, the clearance providing a fluid communication between an interior of a container on which the lotion pump is mounted and the atmosphere, an annular recess for the locking tube portion to thread in being formed between an outside wall surface of the water-ingress-preventing guide sleeve and an inside wall surface of an upper portion of the central through-hole, an internal thread being formed on an inside wall of the central through-hole opposite to the outside wall surface of the water-ingress-preventing guide sleeve, the internal thread being able to engage the external thread on the locking tube portion so as to lock the press head relative to the cylinder cover, 
 wherein the press head has an upper stop position and a lower stop position of a press stroke with respect to the cylinder cover, the lower stop position of the press stroke being defined by a position at which a lower end of the external thread of the locking tube portion abuts against an upper end of the internal thread of the central through-hole during a press stroke of the press head, 
 and wherein at least one longitudinal slot is formed in the locking tube portion, extending at least a part of a length of the locking tube portion from a lower end edge of the locking tube portion, and is disposed such that an upper end of the slot is at a position above the top surface of the cylinder cover when the press head is in the lower stop position relative to cylinder cover. 
 
     
     
       2. The water-ingress-preventing mechanism for a lotion pump of  claim 1 , wherein the external thread of the locking tube portion extends helically upwards from the lower end edge of the locking tube portion, and the internal thread of the central through-hole extends helically downwards from an upper end edge of the central through-hole, whereby the lower end edge of the locking tube portion enters the annular recess of the cylinder cover only by turning the locking tube portion and the cylinder cover with respect to each other, whereas when the press head is pressed down to the lower stop position with respect to the cylinder cover, the lower end edge of the locking tube portion only abuts against the upper end edge of the central through-hole of the cylinder cover but does not enter the annular recess. 
     
     
       3. The water-ingress-preventing mechanism for a lotion pump of  claim 1 , wherein the lower end opening of the passage in the press head is formed by a tube-like joint portion extending downwards from the body of the press head, the connecting conduit is connected to the press head body by being inserted into or fitted over the tube-like joint portion so as to provide a continuous outside wall surface that forms a slide fit with the inside wall surface of the water-ingress-preventing guide sleeve, and the locking tube portion surrounds the tube-like joint portion to form therebetween an annular groove for the water-ingress-preventing guide sleeve to be inserted therein. 
     
     
       4. The water-ingress-preventing mechanism for a lotion pump of  claim 3 , wherein on the outside wall surface of the tube-like joint portion or the connecting conduit, or on an inside wall surface of the locking tube portion, is formed an annular rib, which is positioned such that when the lower end edge of the locking tube portion is pressed downwards to the level of the top surface of the cylinder cover, the annular rib has been diametrically engaged with the inside wall surface of an upper end portion of the water-ingress-preventing guide sleeve so as to create a sealing which blocks off fluid communication between the interior of the container and the atmosphere. 
     
     
       5. The water-ingress-preventing mechanism for a lotion pump of  claim 1 , wherein the thickness of both the locking tube portion and the water-ingress-preventing guide sleeve is made such that when the external thread on the outside wall of the locking tube portion is engaged with the internal thread of the central through-hole, an inside wall surface of the locking tube portion and the outside wall surface of the water-ingress-preventing guide sleeve are in contact with each other. 
     
     
       6. The water-ingress-preventing mechanism for a lotion pump of  claim 1 , wherein the at least one longitudinal slot extends over the whole length of the locking tube portion. 
     
     
       7. The water-ingress-preventing mechanism for a lotion pump of  claim 1 , wherein the water-ingress-preventing guide sleeve is formed integrally with the cylinder cover. 
     
     
       8. The water-ingress-preventing mechanism for a lotion pump of  claim 2 , wherein the internal thread and the external thread each are a multi-start thread. 
     
     
       9. A water-ingress-preventing mechanism for a lotion pump, comprising:
 a press head, in which a passage is formed, a locking tube portion being formed around a lower end opening of the passage and vertically extending downwards from a body of the press head, an external thread being formed on an outside wall of the locking tube portion; 
 a connecting conduit, an upper end of which is fixed to the lower end opening of the passage of the press head so as to communicate with the passage; and 
 a cylinder cover, which has a central through-hole for the connecting conduit to pass, a water-ingress-preventing guide sleeve being provided on an inside wall surface of a lower portion of the central through-hole to vertically extend beyond a top surface of the cylinder cover, the fit between an inside wall surface of the water-ingress-preventing guide sleeve and an outside wall surface of the connecting conduit being a slide fit with a clearance therebetween, the clearance providing a fluid communication between an interior of a container on which the lotion pump is mounted and the atmosphere, an annular recess for the locking tube portion to thread in being formed between an outside wall surface of the water-ingress-preventing guide sleeve and an inside wall surface of an upper portion of the central through-hole, an internal thread being formed on an inside wall of the central through-hole opposite to the outside wall surface of the water-ingress-preventing guide sleeve, the internal thread being able to engage the external thread on the locking tube portion so as to lock the press head relative to the cylinder cover, 
 wherein the press head has an upper stop position and a lower stop position of a press stroke with respect to the cylinder cover, the lower stop position of the press stroke being defined by a position at which a lower end of the external thread of the locking tube portion abuts against an upper end of the internal thread of the central through-hole during the press stroke of the press head, 
 wherein the external thread of the locking tube portion extends helically upwards from a lower end edge of the locking tube portion, and the internal thread of the central through-hole extends helically downwards from an upper end edge of the central through-hole, whereby the lower end edge of the locking tube portion enters the annular recess of the cylinder cover only by turning the locking tube portion and the cylinder cover with respect to each other, whereas when the press head is pressed down to the lower stop position with respect to the cylinder cover, the lower end edge of the locking tube portion only abuts against the upper end edge of the central through-hole of the cylinder cover but does not enter the annular recess, 
 wherein the lower end opening of the passage in the press head is formed by a tube-like joint portion extending downwards from the body of the press head, the connecting conduit is connected to the press head body by being inserted into or fitted over the tube-like joint portion so as to provide a continuous outside wall surface that forms a slide fit with the inside wall surface of the water-ingress-preventing guide sleeve, and the locking tube portion surrounds the tube-like joint portion to form therebetween an annular groove for the water-ingress-preventing guide sleeve to be inserted therein, and 
 wherein on the outside wall surface of the tube-like joint portion or the connecting conduit, or on an inside wall surface of the locking tube portion, is formed an annular rib, which is positioned such that when the lower end edge of the locking tube portion is pressed downwards to the level of the top surface of the cylinder cover, but does not enter the annular recess to lock the press head relative to the cylinder cover, the annular rib has been diametrically engaged with an upper end portion of the water-ingress-preventing guide sleeve so as to create a sealing which blocks off fluid communication between the interior of the container and the atmosphere, and 
 wherein at least one longitudinal slot is formed in the locking tube portion, extending at least a part of a length of the locking tube portion from a lower end edge of the locking tube portion. 
 
     
     
       10. The water-ingress-preventing mechanism for a lotion pump of  claim 9 , wherein the at least one longitudinal slot extends over the whole length of the locking tube portion. 
     
     
       11. The water-ingress-preventing mechanism for a lotion pump of  claim 9 , wherein the thickness of both the locking tube portion and the water-ingress-preventing guide sleeve is made such that when the external thread of the outside wall of the locking tube portion is engaged with the internal thread of the central through-hole, an inside wall surface of the locking tube portion and the outside wall surface of the water-ingress-preventing guide sleeve are in contact with each other. 
     
     
       12. The water-ingress-preventing mechanism for a lotion pump of  claim 9 , wherein the water-ingress-preventing guide sleeve is formed integrally with the cylinder cover. 
     
     
       13. The water-ingress-preventing mechanism for a lotion pump of  claim 9 , wherein the internal thread and the external thread each are a multi-start thread. 
     
     
       14. A water-ingress-preventing mechanism for a lotion pump, comprising:
 a press head, in which a passage is formed, a locking tube portion being formed around a lower end opening of the passage and vertically extending downwards from a body of the press head, an external thread being formed on an outside wall of the locking tube portion; 
 a connecting conduit, an upper end of which is fixed to the lower end opening of the passage of the press head so as to communicate with the passage; and 
 a cylinder cover, which has a central through-hole for the connecting conduit to pass, a water-ingress-preventing guide sleeve being provided on an inside wall surface of a lower portion of the central through-hole to vertically extend beyond a top surface of the cylinder cover, the fit between an inside wall surface of the water-ingress-preventing guide sleeve and an outside wall surface of the connecting conduit being a slide fit with a clearance therebetween, the clearance providing a fluid communication between an interior of a container on which the lotion pump is mounted and the atmosphere, an annular recess for the locking tube portion to thread in being formed between an outside wall surface of the water-ingress-preventing guide sleeve and an inside wall surface of an upper portion of the central through-hole, an internal thread being formed on an inside wall of the central through-hole opposite to the outside wall surface of the water-ingress-preventing guide sleeve, the internal thread being able to engage the external thread on the locking tube portion so as to lock the press head relative to the cylinder cover, 
 wherein the press head has an upper stop position and a lower stop position of a press stroke with respect to the cylinder cover, the lower stop position of the press stroke being defined by a position at which a lower end of the external thread of the locking tube portion abuts against an upper end of the internal thread of the central through-hole during the press stroke of the press head, 
 wherein the external thread of the locking tube portion extends helically upwards from a lower end edge of the locking tube portion, and the internal thread of the central through-hole extends helically downwards from an upper end edge of the central through-hole, whereby the lower end edge of the locking tube portion enters the annular recess of the cylinder cover only by turning the locking tube portion and the cylinder cover with respect to each other, whereas when the press head is pressed down to the lower stop position with respect to the cylinder cover, the lower end edge of the locking tube portion only abuts against the upper end edge of the central through-hole of the cylinder cover but does not enter the annular recess, and 
 wherein at least one longitudinal slot is formed in the locking tube portion, extending at least a part of a length of the locking tube portion from a lower end edge of the locking tube portion. 
 
     
     
       15. The water-ingress-preventing mechanism for a lotion pump of  claim 14 , wherein the at least one longitudinal slot extends over the whole length of the locking tube portion. 
     
     
       16. The water-ingress-preventing mechanism for a lotion pump of  claim 9 , wherein the annular rib is disposed on an outside wall surface of the tube-like joint portion for diametrically engaging with the inside wall surface of the upper end portion of the water-ingress-preventing guide sleeve.